Drones are widely used in the ‘war on terror’. Unmanned airplanes with hellfire missiles on board, controlled from another country, they kill from the sky.

Drones and drone warfare are highly controversial – on ethical, legal and utilitarian grounds – as Andrew Cockburn explains in this conversation with Craig Barfoot about his latest book Kill Chain. Cockburn is an assiduous investigator and delivers a trenchant critique of the people he calls the ‘High Tech Assassins’.